Industrial lift trucks, such as forklift trucks, an example 1 of which is shown in FIG. 1, typically include a body 3 housing the operator 2, controls and means of propulsion over a surface 0, and a mast assembly 4. The mast assembly carries the forks 5 or other lifting attachments which are movable up and down the mast assembly. As illustrated in FIG. 2, the mast assembly is mounted such that it can be pivoted relative to the truck body, and thereby the angle of the forks can be changed by adjusting the tilt angle of the mast.
Operators of such industrial lift trucks generally have difficulty in determining the required tilt angle of the mast to align the angle of the forks with the load that is to be lifted. This in the main is due to the orientation of tilt being parallel to the operator's line of sight from the operating position. The operator therefore receives limited visual indication of the tilt angle. This is exacerbated as the mast is extended vertically.
Correct alignment of the forks requires a high degree of operator skill and frequent fine adjustment of the mast tilt controls. Inevitably there are occasions when the operator fails to correctly align the forks with the load.
The consequences of misaligned forks can be damage to the pallet being lifted, damage to the load on the pallet, damage to racking systems and personal injury. Each of these have significant associated costs.